namechangesforthehardstuff hi, my dear it is obvious you are rather worried about this and I think you probably don't need to be.
Here is my perspective, ignore it is you like. My dd was 2 when we stated looking into this process so for several years (she is now 9) we kind of drip fed things in about adoption. By the time she was 7 we knew that we were definitely not going to have another birth child and adoption would be our only option. By 8 she was 'interviewed'. Now I know 8 is a lot older than 3 but as our daughter has dyslexia she is really quite young for her age and would have been more like a 5 or 6 year old in terms of some of her activities and understanding, (older in terms of others) at that stage. She is catching up now but for quiet a while was quite young for her age.
We made sure she always knew adoption was something we wanted to do as a family but the decision was dependant on us being accepted and a suitable child being found, neither of which were within our control. Choose your own language but I don't think it is a bad thing for any child to know that something, moving to a specific house, good grades at school or a birth brother or sister is, like a child joining your family by adoption, are not necessarily things we can guarantee. Does that make sense? We talked about wanting it to happen; hoping it would but that we were happy as a family of three, we were a complete unit and if it was not meant to be then it would also be fine.
Secondly, by the time our social worker met our daughter specifically she had already met her with us in passing on about 5 occasions. I made DD say hi etc and I think it helped for her to know who social worker was before she actually met her 'alone'.
When DD met her 'alone' she arrived with potted plants for the garden as as gift for DD, colouring sheets and coloured pencils. She sat n the dining room with DD up the table and drew pictures and talked in the most general terms about adoption and then about what kind of child DD would imagine joining the family. While I stayed in our living room, with the adjoining door partially open and sat at my computer (straining to hear what was said!).
It was all fine and at the end I joined DD and SW and then DD said loudly whispering in my ear 'Can we stop talking now?' before she was off to watch TV in the living room. It was totally fine and not a problem at all.
Finally, I would say although you are worried, your DD will probably take her cue from you so try not to pass on your worry. I would be very surprised if you application to adopt will be dependent on your DD at all but it is a process they need to go through and if you come across as very anxious about this isn't there a chance it could be misinterpreted as worry about what your DD will say. I don't mean that in a nasty sense just a worry that she may say she does not want you to adopt?
I have no reason to believe that the social worker thinking this would be the case but I am just saying if you come across as very worried it may look 'bad'.
Hopefully, it will be what it was for us, a very simple and short chat rather than an over the top interview. If you are concerned I would just couch it in the language of not wanting to let your DD get her hopes up etc and ask the social worker if you can find out the kind of things she will be asked just so you will know if DD later says anything about it you will know what she is talking about. I think that sounds reasonable.
Devora good Lord Missey that is very funny and I think you probably have got the best social worker quote I have ever heard!